System and method for locating nodes within a wireless network

Patent metadata

Field	Value
Publication number	US-9716979-B2
Application number	US-201414568332-A
Country	US
Kind code	B2
Filing date	Dec 12, 2014
Priority date	Dec 12, 2014
Publication date	Jul 25, 2017
Grant date	Jul 25, 2017

Abstract

A system and method for determining the location of nodes within a network. Beamforming coefficients associated with signals transmitted from a first node to a second node are determined and, based on the beamforming coefficients, direction is determined between the first and second nodes. Distance is determined as a function of direction and the location of the second node is determined as a function of distance and direction.

First claim

What is claimed is:

1. In a network having first and second network devices, a method of determining the location of the second network device using only the first and second network devices, the method comprising:
determining beamforming coefficients associated with signals transmitted from the first network device to the second network device;
determining a direction of the second network device relative to the first network device using the beamforming coefficients;
determining a distance between the first network device and the second network device as a function of time of flight and direction, including:
transmitting, via the first network device, a request-to-send signal to the second network device; and
receiving, via the first network device, a clear-to-send signal from the second network device; and

determining a location of the second network device as a function of the determined distance and direction.

2. The method of claim 1 , wherein determining a distance includes determining a round trip delay of a signal from one of the first and second network devices to the other of the first and second network devices.

3. The method of claim 1 , wherein determining a distance includes making a four-way time-of-arrival (TOA) determination.

4. The method of claim 1 , wherein determining a distance includes determining time of flight as a function of a continuous distribution of time of flight measurements.

5. The method of claim 1 , wherein determining a distance includes monitoring transmissions between the first and second network devices via a third network device; and
calculating, based on measurements at the second network device, a time of flight between the first and second network devices.

6. The method of claim 1 , wherein determining a distance includes determining if the first or second network device is moving and adjusting direction accordingly.

7. The method of claim 1 , wherein determining direction includes determining direction using each of two different bands.

8. In a network having first; second and third network devices a method of determining the location of the second network device, the method comprising:
determining beamforming coefficients associated with signals transmitted from the first network device to the second network device and beamforming coefficients associated with signals transmitted from the third network device to the second network device;
determining a direction of the second network device from the first and third network devices using the beamforming coefficients; and
determining a location of the second network device as a function of direction from each of the first and third network devices and the location of the first and third network devices, including:
determining a distance between the first network device and the second network device as a function of time of flight and direction, including
transmitting, via the first network device, a request-to-send signal to the second network device; and
receiving, via the first network device, a clear-to-send signal from the second network device;

determining a distance between the third network device and the second network device as a function of time of flight and direction, including:
transmitting, via the third network device, a request-to-send signal to the second network device; and
receiving, via the third device, a clear-to-send signal from the second network device; and

determining a location of the second network device as a function of direction and distance from each of the first and third network devices and of triangulation from the first and third network devices.

9. The method of claim 8 , wherein determining a distance includes determining round trip delay of a signal from one of the first and second network devices to the other of the first and second network devices.

10. The method of claim 8 , wherein determining a distance includes making a four-way time-of-arrival (TOA) determination.

11. The method of claim 8 , wherein determining a distance includes determining a time of flight as a function of a continuous distribution of time of flight measurements.

12. The method of claim 8 , wherein determining a distance includes monitoring transmissions between the first and second network devices via a third network device; and
calculating, based on measurements at the second network device, tune of flight between the first and second network devices.

13. The method of claim 8 , wherein determining a distance includes determining if the first or second network device is moving and adjusting direction accordingly.

14. The method of claim 8 , wherein determining a direction includes determining a direction using each of two different bands.

Assignees

• Calix Inc

Inventors

• Roberts Harold
• Buffum Jeffrey
• Dove Jason

Classifications

• H04W4/025 Primary

  using location based information parameters · CPC title

• G01S5/12

  by co-ordinating position lines of different shape, e.g. hyperbolic, circular, elliptical or radial · CPC title

• H04W72/046

  the resource being in the space domain, e.g. beams · CPC title

• G01S5/08

  Position of single direction-finder fixed by determining direction of a plurality of spaced sources of known location · CPC title